Added details about pcdx problem

git-svn-id: https://smartmontools.svn.sourceforge.net/svnroot/smartmontools/trunk@390 4ea69e1a-61f1-4043-bf83-b5c94c648137

sm5/WARNINGS

@@ -11,3 +11,5 @@ PROBLEM:  Smartctl locks system solid when used on /dev/hd[ef].
 REPORTER: Georg Acher <acher@in.tum.de>
 LINK:     http://sourceforge.net/mailarchive/forum.php?thread_id=1457979&forum_id=12495
 NOTE:     Lockup doesn't happen with 2.4.18 kernel, and doesn't affect /dev/hd[a-d]
+          This appears to be a problem with the pdc202xx-driver and has been reported
+          to the pcdx maintainers.